JP2014082739A - Gateway device, communication device, and communication connection management method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gateway device which can perform priority control depending on the priority of communication connection, even if the number of communication connections has an upper limit, and to provide a communication device, and a communication connection management method.SOLUTION: A gateway device includes a priority identification information table B storing the information of priority of communication connection, with a part of information included in a packet as the identification information, a communication connection management table A storing the identification information, and the information of priority corresponding to the identification information, for every communication connection being established between the terminal and communication network and gateway device, and a communication connection priority control section 1 for acquiring the information of priority of a communication connection corresponding to a packet being transmitted and received, based on the information of the priority identification information table B, and performing priority control of communication connection depending on the level of priority so that the number of communication connections does not exceed an upper limit.

Description

  The present invention relates to a gateway device, a communication device, and a communication connection management method that accommodate a plurality of terminals and relay packets between the terminals and a communication network.

  As a prioritized control method of a conventional gateway device, for example, as disclosed in Patent Document 1, a plurality of SIP terminals are accommodated, and the SIP terminal and an external network having an upper limit on the number of sessions that can be connected simultaneously When all available sessions are in use and a connection request for a new session with higher importance is received, the priority of each connected session is checked and There is a communication session priority control method at an application level in which a session with the lowest priority is disconnected and a new session is connected.

JP 2011-114678 A

  However, in communication devices such as gateway devices, there is a problem that priority control of communication sessions cannot always be performed in the priority control method at each application level, as in the technique described in Patent Document 1. That is, in the communication device such as the gateway device, an upper limit of the number of communication connections as a whole device that can be managed by the communication device itself is set apart from the upper limit value of the number of communication sessions in each application. Communication connections are managed at the kernel level, and the upper limit of the number of communication connections is set in consideration of the upper limit value depending on the memory capacity installed in the communication device.

  Even if a device in which priority control at the application level is implemented as in the technique described in Patent Document 1, if the upper limit of the number of communication connections as the entire device has been reached, new communication is performed. When a connection packet (for example, a session connection request) is received, due to the restriction on the number of communication connections that can be handled as a device, the operation is to discard a new communication connection packet (session connection request) at the kernel level. There is a problem that a connection request for a new session does not reach the level, and priority control cannot be performed even if the new communication connection has high priority.

  In recent years, a gateway device (hereinafter referred to as “home gateway”) interposed between a home network and a public line network has been accompanied by the expansion of services such as IP (Internet Protocol) telephone, IPTV (Internet Protocol TeleVision), and the Internet. A lower terminal accommodated in a gateway device (HGW) can also accommodate a PC (Personal Computer) terminal, an IP telephone terminal, an STB (Set Top Box) terminal, a DLNA (Digital Living Network Alliance) device, and the like. The number of communication connections through the device is increasing.

  In the home gateway device, for example, in a state where a plurality of PC terminals for the Internet are accommodated on the LAN (Local Area Network) side and an IP telephone terminal for the IP telephone is accommodated, the number of communication connections by the plurality of PC terminals When using best-effort services using P2P (Peer to Peer) software, etc. that use a large amount of data, the number of communication connections reaches the upper limit of the number of communication connections for the entire device, and A problem arises in that a packet (session connection request) for a new communication connection cannot be received, and an IP phone or the like, which is a chargeable guarantee type service, cannot be used.

  Therefore, there has been a demand for a gateway device, a communication device, and a communication connection management method capable of performing priority control according to the priority of communication connections even when there is an upper limit on the number of communication connections.

  In addition, since today's home gateway devices require high-speed communication such as “two-way communication total 2 Gbps”, a fast path core dedicated to high-speed packet transfer is generally installed separately from the core that processes the kernel. Is. The communication connection described above also exists in the fast path core, and if the fast path communication connection exists on the fast path core, it is a mechanism that enables high-speed transfer.

Therefore, a gateway device, a communication device, and a communication connection management method that can perform priority control according to the priority in a communication connection (fast path communication connection) that is a target of high-speed transfer have been desired.
The fast path core may use less memory than the core that processes the kernel, and the upper limit of the fast path communication connection may be smaller than the upper limit of the communication connection. Even in this case, a gateway device, a communication device, and a communication connection management method capable of performing priority control according to the priority have been desired.

  The gateway device according to the present invention accommodates a plurality of terminals, relays packets between the terminal and the communication network, and receives when the number of communication connections between the terminal and the communication network exceeds an upper limit. A gateway device that discards a packet, using a part of information included in the packet as identification information, a priority identification information table storing priority information of a communication connection, the terminal, the communication network, and the For each communication connection established with the gateway device, the identification information, the communication connection management table storing the priority information corresponding to the identification information, and the information of the priority identification information table Based on the priority of the communication connection corresponding to the packet to be sent and received, the number of communication connections does not exceed the upper limit. , Depending on the level of the priority, to the communication connection priority control section for preferentially controlling the communication connection, comprising the.

  A communication apparatus according to the present invention is a communication apparatus that transmits and receives packets to and from a plurality of terminals, and discards received packets when the number of communication connections with the terminals exceeds an upper limit. A part of the included information is used as identification information, a priority identification information table in which information of communication connection priority is stored, and for each communication connection established between the terminal and the communication device, the identification information And the priority information of the communication connection corresponding to the packet to be transmitted / received based on the communication connection management table storing the priority information corresponding to the identification information and the information of the priority identification information table In order to prevent the number of communication connections from exceeding the upper limit, a communication connection that preferentially controls communication connections according to the level of the priority. A priority control unit, characterized by comprising a.

  A communication connection management method according to the present invention is a communication connection management method for a communication device that transmits and receives packets to and from a plurality of terminals, and discards received packets when the number of communication connections with the terminals exceeds an upper limit. And, with a part of information included in the packet as identification information, the step of setting communication connection priority information, and for each communication connection established between the terminal and the communication device, Creating the identification information and priority information corresponding to the identification information; obtaining communication connection priority information corresponding to a packet to be transmitted / received; and preventing the number of communication connections from exceeding an upper limit. And a step of preferentially controlling the communication connection in accordance with the level of the priority.

  The present invention can perform priority control according to the priority of communication connections even when there is an upper limit on the number of communication connections.

1 is a configuration diagram of a home gateway device in Embodiment 1. FIG. FIG. 3 is a diagram showing a configuration of a communication connection management table A in the first embodiment. 6 is a diagram showing a configuration of a priority identification information table B in the first embodiment. FIG. 4 is a flowchart illustrating an operation of a communication connection priority control unit 1 according to the first embodiment. 6 is a diagram showing a specific example of a priority identification information table B in the first embodiment. FIG. FIG. 6 is a sequence diagram showing a specific example of priority control operation in the first embodiment. FIG. 6 is a configuration diagram of a home gateway device in a second embodiment. FIG. 10 is a diagram showing a configuration of a fast path communication connection management table C in the second embodiment. 10 is a flowchart showing a packet transmission / reception operation in the second embodiment. 10 is a flowchart showing fast path communication connection processing in the second embodiment. FIG. 10 is a diagram showing a specific example of a priority identification information table B in the second embodiment. FIG. 10 is a sequence diagram illustrating a specific example of a priority control operation in the second embodiment.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram of a home gateway device according to the first embodiment.
As shown in FIG. 1, the home gateway apparatus 100 includes a WAN (Wide Area Network) port 10, a LAN port 20, a user space application 30, and a kernel 40.
For example, a network side NW (Network) 200 is connected to the WAN port 10. A PC terminal 300 and an IP telephone terminal 400 are connected to the LAN port 20.
The user space application 30 includes applications related to communication control such as a VoIP (Voice over Internet Protocol) application, an HTTP (HyperText Transfer Protocol) application, a DNS (Domain Name Server) Proxy application, and a UPnP (Universal Plug and Play) application. .

The kernel 40 is software in which basic functions of an OS (Operating System) are installed, and provides basic functions such as application monitoring, management of resources such as memory, and interrupt processing. In the kernel 40, an upper limit value of the number of communication connections that can be handled as a device is set, and when the number of communication connections exceeds the upper limit, the received packet is discarded. That is, the upper limit value of the number of communication connections that can be handled as a device is the system memory (memory space (physical memory (main storage device) managed by the kernel) or the system memory in the memory (main storage device or auxiliary storage device) mounted on the home gateway device 100. Virtual memory (main storage device + part of auxiliary storage device)))).
The upper limit value of the number of communication connections that can be handled as a device in the configuration of FIG. 1 is the number of communication connections that can be established between the network side NW 200, each PC terminal 300, and the IP telephone terminal 400 and the home gateway device 100. For example, when the kernel 40 manages a free 64 MB of the system memory and consumes 320 bytes of memory per communication connection when managing the communication connection, the kernel 40 sets 209715 (67108864 (64 × 1024 × 1024) (Byte). ÷ 320 (Byte) = 209971. 2) or less can be applied as the upper limit value of the number of communication connections. For example, in the kernel 40, the upper limit value of the number of communication connections is set to 4096, and the network side NW 200, each PC terminal 300, and the home gateway apparatus 100 as a whole have reached the upper limit value. Even if an attempt is made to establish a new communication connection between the IP telephone terminal 400 and the home gateway device 100, it is discarded.

  The kernel 40 also performs network address conversion (conversion of IP, port number, etc.) between the WAN port 10 (network side NW200) and the LAN port 20 (each PC terminal 300 and IP telephone terminal 400). It may have a conversion (NAT (Network Address Translation) or NAPT (Network Address Port Translation)) means. In this case, when the packet received by the kernel 40 is not discarded, the packet may be relayed while performing network address conversion.

  In addition, the upper limit value of the number of communication connections that can be handled as a device is the number of communication connections that can be established between the network side NW 200, each PC terminal 300, and the IP telephone terminal 400 via the home gateway device 100 (with the WAN port 10). (The number of communication connections that can be established with the LAN port 20). In this case, when the kernel 40 has network address conversion means, the upper limit value of the number of communication connections that can be handled by the network address conversion means may be set as the upper limit value of the number of communication connections that can be handled as a device. For example, in the kernel 40, the upper limit value of the number of communication connections is set to 4096, and the number of communication connections (the number of communication connections that can be handled by the network address conversion unit) as the entire home gateway apparatus 100 has reached the upper limit value. Even if an attempt is made to establish a new communication connection between the network side NW 200, each PC terminal 300, and the IP telephone terminal 400, it is discarded.

  The kernel 40 also includes a communication connection priority control unit 1 that controls management of communication connections in the home gateway device 100. The communication connection priority control unit 1 includes a communication connection management table A and a priority identification information table B.

  In the first embodiment, a configuration in which the kernel 40 includes the communication connection priority control unit 1 and the communication connection priority control unit 1 includes the communication connection management table A and the priority identification information table B will be described. The communication connection priority control unit 1 may be provided separately from the kernel 40, or the communication connection management table A and the priority identification information table B may be provided in separate storage areas.

FIG. 2 is a diagram showing a configuration of the communication connection management table A in the first embodiment.
As shown in FIG. 2, information managed by the communication connection management table A includes information such as a Layer 3 protocol, a Layer 4 protocol, a source address, a source port number, a destination IP address, and a destination port number. Information is held and communication connections are managed. Further, in the first embodiment, in order to hold the priority of each communication connection, a priority area is provided to enable management of the communication connection priority for each communication connection.
Generally, in the communication connection entry, a timer to be maintained for each Layer 4 protocol is set, and when the timer expires, the entry is deleted.
As described above, the communication connection management table A includes the identification information and the identification information for each communication connection established between the network side NW 200, each PC terminal 300, and the IP telephone terminal 400 and the home gateway device 100. Corresponding priority information is stored. That is, the communication connection management table A manages communication connections as the home gateway device 100 as a whole.

  Note that if the kernel 40 sets the upper limit of the number of communication connections that can be handled as a device as the number of communication connections that can be established between the network side NW 200, each PC terminal 300, and the IP telephone terminal 400, the communication The connection management table A corresponds to the identification information and the identification information for each communication connection between the network side NW 200 and each PC terminal 300 and IP telephone terminal 400 among the communication connections of the home gateway apparatus 100 as a whole. The priority information to be stored may be stored. In this case, the communication connection between the WAN port 10 and the LAN port 20 in the communication related to the home gateway device 100 is managed by the communication connection management table A.

FIG. 3 is a diagram showing a configuration of the priority identification information table B in the first embodiment.
As shown in FIG. 3, in the priority identification information table B, communication connection identification information and priority information corresponding thereto are held as one entry, and a plurality of entries are held as a table. The identification information of the communication connection is constituted by a part of information included in the packet, and is, for example, at least one information of the IP header, TCP / UDP / ICMP header, and destination port of the packet.
This priority identification information table B may be information stored in advance as a device, or may be provided individually by a user by providing a user setting interface.

  Note that when the upper limit value of the number of communication connections that can be handled as a device is the number of communication connections that can be established between the network side NW 200, each PC terminal 300, and the IP telephone terminal 400 and the home gateway device 100, the priority The identification information of the communication connection in the identification information table B includes the IP header, the TCP / UDP / ICMP header included in the packet transmitted and received by each of the network side NW 200, each PC terminal 300, the IP telephone terminal 400, and the home gateway device 100, And at least one piece of information on the destination port. In this way, priority (priority packet processing) can be given to packets exchanged between network side NW200, each PC terminal 300, and IP telephone terminal 400 and home gateway apparatus 100.

  When the upper limit value of the number of communication connections that can be handled as a device is the number of communication connections that can be established between the network side NW 200, each PC terminal 300, and the IP telephone terminal 400 via the home gateway device 100, The IP header included in the packet transmitted and received by each of the network side NW 200, each PC terminal 300, and the IP telephone terminal 400 that exchanges the communication connection identification information in the priority identification information table B via the home gateway device 100, TCP The information may be at least one of the / UDP / ICMP header and the destination port. In this way, priority (priority packet processing) can be given to packets exchanged through the home gateway device 100.

  When the kernel 40 has network address conversion means, the communication connection identification information in the priority identification information table B is used as the IP header, TCP / UDP / The information may be at least one of an ICMP header and a destination port. In this way, a priority (priority packet processing) can be given to a packet whose network address is translated by the network address translation means.

  The priority information may be any information that can identify the priority level, and may be any information such as a numerical value, a symbol, or a character string. In the first embodiment, a case will be described in which the higher the numerical value, the higher the priority, and the lower the numerical value, the lower the priority.

  Next, the communication connection management operation of the communication connection priority control unit 1 in the first embodiment will be described.

FIG. 4 is a flowchart showing the operation of the communication connection priority control unit 1 in the first embodiment. Hereinafter, a description will be given based on each step of FIG.
(S1)
When a packet is received from network side NW 200, each PC terminal 300, and IP telephone terminal 400, or when a packet is transmitted from the home gateway device (hereinafter referred to as "transmission / reception"), communication connection priority control unit 1 Starts the communication connection management operation.
(S2)
The communication connection priority control unit 1 refers to the communication connection management table A, confirms whether the information of the IP header and TCP / UDP / ICMP header of the packet to be transmitted / received is already registered in the communication connection management table A, and registers If not, it is determined that the communication connection is new.
(S3)
When a communication connection corresponding to a packet to be transmitted / received is already registered in the communication connection management table A, normal packet processing is continued.

(S4)
On the other hand, in the case of a packet of a new communication connection, it is confirmed whether or not the total number of communication connections has reached the upper limit of manageable communication connections.
(S5)
If the upper limit is not reached, it is confirmed whether the information in the IP header and TCP / UDP / ICMP header of the packet to be transmitted / received matches the identification information in the priority identification information table B.
If the identification information in the priority identification information table B matches the information of the packet to be transmitted / received, the process proceeds to step S11.
(S6)
If the identification information in the priority identification information table B does not match the packet information to be transmitted / received, the new communication connection information is registered in the communication connection management table A. At this time, the total number of communication connections is updated (added), and “0” is set as priority information in the communication connection management table A. Thereafter, the process proceeds to step S12.
Here, “0” is set as the priority information, but the present invention is not limited to this, and a priority lower than the lowest priority among the priorities of the entries in the priority identification information table B is set. do it.

(S7)
If it is determined in step S4 that the number of communication connections has reached the upper limit, it is confirmed whether the information in the IP header and TCP / UDP / ICMP header of the packet to be transmitted / received matches the identification information in the priority identification information table B To do.
(S8)
If the identification information in the priority identification information table B does not match the information of the packet to be transmitted / received, it is determined that the packet is a low priority packet and the packet is discarded.

(S9)
On the other hand, if the identification information in the priority identification information table B matches the information of the packet to be transmitted / received, the priority information of the new communication connection corresponding to the packet is acquired, and the communication connection management table A It is determined whether or not there is a communication connection lower than the priority of the new communication connection among the priorities of the registered communication connections.
If there is no communication connection lower than the priority of the new communication connection, the process proceeds to step S8, where it is determined that the packet is a low priority packet, and the packet is discarded.

(S10)
On the other hand, if there is a communication connection lower than the priority of the new communication connection, the communication connection entry with the lowest priority is deleted from the communication connection priorities registered in the communication connection management table A, and the communication connection Update the total number (delete one). When there are a plurality of communication connections set with the lowest priority, any one is deleted.

(S11)
The new communication connection information is registered in the communication connection management table A. At this time, the total number of communication connections is updated (added one), and the priority information corresponding to the identification information in the priority identification information table B matched in step S7 is used as the priority information in the communication connection management table A. Set.

(S12)
After the above processing, normal packet processing is continued.

As described above, the communication connection priority control unit 1 acquires the priority information of the communication connection corresponding to the packet to be transmitted / received based on the information of the priority identification information table B so that the number of communication connections does not exceed the upper limit. The communication connection is preferentially controlled according to the priority level.
Therefore, in the first embodiment, even when the number of communication connections reaches the upper limit of manageable communication connections, the priority of the new communication connection is identified at the time of transmission / reception of the packet of the new communication connection, Check the priority of the existing communication connection, and if there is a connection lower than the priority of the new communication connection among the existing communication connections, delete the corresponding existing connection, A high new communication connection can be prioritized.
In the first embodiment, when the kernel 40 has the network address conversion means, the network address conversion means performs network address conversion when the communication connection priority control unit 1 continues normal packet processing (S3 or S12). The packet may be relayed while performing the above.

  Next, a specific example of the operation when the communication of the IP telephone terminal 400 is prioritized over the communication of the PC terminal 300 in the home gateway apparatus 100 accommodating the PC terminal 300 and the IP telephone terminal 400 will be described.

  Here, as shown in FIG. 1, a plurality of PC terminals 300 for the Internet are accommodated on the LAN side of the home gateway apparatus 100, and a plurality of IP telephone terminals 400 for IP telephones are accommodated. A description will be given assuming that P2P software or the like is used in a single PC terminal 300.

  In the state where the number of communication connections of the best effort type Internet communication in the PC terminal 300 has reached the upper limit (for example, 4096) of the number of communication connections of the home gateway device 100 as a whole, The operation when a communication connection packet (session connection request) is received will be described. Assuming that an IP phone using the IP phone terminal 400 is a guarantee type service, it is assumed that priority should be given to a best effort type service using an Internet connection.

FIG. 5 is a diagram showing a specific example of the priority identification information table B in the first embodiment.
In FIG. The entry 1 is priority identification information in which a packet whose source address is the WAN-side IP address used by the home gateway apparatus 100 (HGW) for the IP telephone service is a priority “10”.
No. The entry of 2 is priority identification information in which a packet whose destination address is the IP address on the WAN side used by the home gateway apparatus 100 (HGW) for the IP telephone service is a priority “10”.
No. The entry 3 is priority identification information in which the IP address of the IP telephone terminal 400 subordinate to the LAN accommodated in the home gateway device 100 (HGW) is a packet whose source address is a priority “10”. .
No. The entry 4 is priority identification information in which the IP address of the IP telephone terminal 400 subordinate to the LAN accommodated in the home gateway device 100 (HGW) is a packet whose destination address is a priority “10”.
Note that the entry of the communication connection corresponding to the packet of the PC terminal 300 is not set. For this reason, “0” is registered in the communication connection management table A as the priority of the communication connection of the PC terminal 300.

FIG. 6 is a sequence diagram showing a specific example of the priority control operation in the first embodiment.
An upper limit of communication connections that can be managed by the home gateway device 100 by communication between the network side NW 200 and the PC terminal 300 (PC (1) to (3)) via the home gateway device 100 (HGW) (for example, 4096), a communication connection priority control operation when a SIP INVITE packet for a session connection request is received from the IP telephone terminal 400 is shown.

  First, the communication connection priority control unit 1 of the home gateway device 100 (IP: 192.168.1.1) receives a SIP INVITE packet (SRC: 192.168.1.2 DST: 192.168.1.1) from the IP telephone terminal 400 (IP: 192.168.1.2). When it is determined that the total number of communication connections has already reached the upper limit of manageable communication connections (for example, 4096), it is confirmed whether the SIP INVITE packet matches the identification information in the priority identification information table B of FIG. To do.

This SIP INVITE packet (SRC: 192.168.1.2 DST: 192.168.1.1) has a source IP address of No. 1 in FIG. Since it matches the entry 3, “10” is acquired as the priority of the new communication connection. Then, from among the communication connections registered in the communication connection management table A, it is confirmed whether there is a communication connection with a priority lower than “10”.
In this case, since the priority of the communication connection using the PC (1) to PC (3) is “0”, any one of the communication connections between the PC (1) to PC (3) and the network side NW200. Is deleted from the communication connection management table A, and the identification information of the communication connection of the SIP INVITE packet is registered in the communication connection management table A. When registering, “10” is set as priority information.

Thus, by performing priority control of the communication connection, the SIP INVITE packet can be passed to the VoIP application waiting for the packet without being discarded by the kernel 40.
The VoIP application processes the SIP INVITE packet and tries to transmit the SIP INVITE packet (SRC: 100.100.1.1 DST: 10.10.1.1) to the WAN side. Note that the priority control is similarly performed in the communication connection priority control unit 1 when a spontaneous packet is transmitted from the home gateway device 100.

  When transmitting a SIP INVITE packet (SRC: 100.100.1.1 DST: 10.10.1.1) to the WAN side, the communication connection priority control unit 1 has already reached the upper limit (for example, 4096) of the number of communication connections that can be managed. Recognize that Then, it is confirmed whether the packet of SIP INVITE (SRC: 100.100.1.1 DST: 10.10.1.1) to be transmitted matches the identification information in the priority identification information table B of FIG.

This SIP INVITE packet (SRC: 100.100.1.1 DST: 10.10.1.1) has a source IP address of No. 1 in FIG. Since it matches the entry 1, “10” is acquired as the priority of the communication connection. Then, from among the communication connections registered in the communication connection management table A, it is confirmed whether there is a communication connection with a priority lower than “10”.
In this case, since the priority of the communication connection using the PC (1) to PC (3) is “0”, any one of the communication connections between the PC (1) to PC (3) and the network side NW200. Is deleted from the communication connection management table A, and the identification information of the communication connection of the SIP INVITE packet is registered in the communication connection management table A. When registering, “10” is set as priority information.
Thereafter, similarly, the communication connection of the SIP 200 OK packet from the network side NW 200 and the SIP ACK packet from the IP telephone terminal 400 is determined to have a high priority of the communication connection using the PC (1) to PC (3). The entry of the communication connection between the PC (1) to PC (3) and the network side NW 200 is deleted from the communication connection management table A.
When a session connection is established between network side NW 200 and IP telephone terminal 400, for example, communication using RTP (Real-time Transport Protocol) is performed.

  As described above, when a packet matching the identification information in the priority identification information table B is transmitted / received, by performing priority control of the communication connection, a packet having a high priority is limited to the upper limit of the number of communication connections as a device. Thus, the problem of being discarded can be avoided.

  As described above, according to the first embodiment, in the home gateway apparatus 100, the communication connection priority control unit 1 is provided, and by managing the priority of each communication connection, the number of connections in communication can be reduced. Even when the maximum number of manageable communication connections has been reached, the priority of existing communication connections is confirmed, and there is a communication connection that is lower than the priority of new communication connections among existing communication connections. In addition, it is possible to give priority to a new communication connection with a high priority by deleting the corresponding existing communication connection.

Embodiment 2. FIG.
FIG. 7 is a configuration diagram of the home gateway device according to the second embodiment.
As shown in FIG. 7, the home gateway apparatus 100 according to the second embodiment includes a dedicated OS 50 for fast path processing in addition to the configuration of the first embodiment.
Other configurations are the same as those of the first embodiment, and the same reference numerals are given to the same portions.

The dedicated OS 50 is mounted on a fast path core dedicated to packet high-speed transfer, such as a LAN driver, micro engine, accelerator processor, and the like. A communication table for fast path processing is provided, and a communication connection (high-speed transfer) matching the communication table is provided. The communication connection to be processed) is fast path processed, and packet transfer is processed at high speed.
In the dedicated OS 50, an upper limit value of the number of communication connections subject to high-speed transfer (fast path communication upper limit number) is set, and when the number of communication connections subject to high-speed transfer exceeds the upper limit, the received packet is discarded. . That is, the upper limit of the fast path communication is the number of communication connections that can be managed in a free space in the memory space (physical memory (main storage device) or virtual memory (main storage device + part of auxiliary storage device)) managed by the dedicated OS 50. Is the upper limit.

  The dedicated OS 50 also includes a fast path communication connection priority control unit 2 that controls management of fast path communication connections. The fast path communication connection priority control unit 2 has a fast path communication connection management table C.

  In the second embodiment, the configuration in which the fast path communication connection priority control unit 2 has the fast path communication connection management table C will be described. However, the present invention is not limited to this, and the fast path communication connection management table C is stored in another memory. It may be provided in the region.

FIG. 8 is a diagram showing a configuration of the fast path communication connection management table C in the second embodiment.
As shown in FIG. 8, the information managed by the fast path communication connection management table C holds information equivalent to the information in the communication connection management table A of the first embodiment.
That is, the fast path communication connection management table C holds information such as the Layer 3 protocol, the Layer 4 protocol, the transmission source address, the transmission source port number, the destination IP address, and the destination port number as identification information of the communication connection. In addition, it is possible to manage the priority of communication connections.

  Next, the packet transmission / reception operation in the second embodiment will be described.

FIG. 9 is a flowchart showing a packet transmission / reception operation in the second embodiment.
Hereinafter, based on each step of FIG. 9, it demonstrates centering on difference with the said Embodiment 1 (FIG. 4). In addition, the same step number is attached | subjected to the step same as the said Embodiment 1, and description is abbreviate | omitted.

(S21)
The fast path communication connection priority control unit 2 refers to the fast path communication connection management table C, and information on the IP header and TCP / UDP / ICMP header of the packet to be transmitted / received is already registered in the fast path communication connection management table C. Make sure that If not registered, the process proceeds to step S2.

(S22)
On the other hand, when the fast path communication connection corresponding to the packet to be transmitted / received is already registered in the fast path communication connection management table C, the dedicated OS 50 performs high speed packet transfer and continues normal fast path packet processing.

(S23)
After step S10, the fast path communication connection priority control unit 2 deletes the fast path communication connection corresponding to the communication connection deleted in step S10 from the communication connection entries registered in the fast path communication connection management table C. .

(S24)
After step S6 or step S11, the fast path communication connection priority control unit 2 performs a fast path communication connection process. Details will be described with reference to FIG.

FIG. 10 is a flowchart showing fast path communication connection processing according to the second embodiment. Hereinafter, a description will be given based on each step of FIG.
(S241)
The fast path communication connection priority control unit 2 determines whether or not the new communication connection is a communication connection that can be transferred by fast path. Here, connections that can be transferred by fast path are basically “transfer packets”, and do not include “spontaneous packets”, “self-addressed packets”, and “packets terminating at the own device”.
If it is not a communication connection that can be transferred by fast path, the fast path communication connection process is terminated and the process proceeds to step S12 (FIG. 9).

(S242)
In the case of a communication connection that can be transferred by fast path, it is checked whether the total number of fast path communication connections has reached the maximum number of fast path communication connections that can be managed (the maximum number of fast path communication). If the upper limit has not been reached, the process proceeds to step S245.

(S243)
When it is determined that the number of fast path communication connections has reached the upper limit, the priority identification information table B is referred to, information on the priority of a new fast path communication connection corresponding to the packet is obtained, and the fast path communication connection It is determined whether or not there is a fast path communication connection lower than the priority of the new fast path communication connection among the priorities of the fast path communication connections registered in the management table C.
If there is no communication connection lower than the priority of the new fast path communication connection, the fast path communication connection process is terminated, and the process proceeds to step S12 (FIG. 9).

(S244)
On the other hand, when there is a fast path communication connection lower than the priority of the new fast path communication connection, the lowest priority fast path communication connection among the communication connection priorities registered in the fast path communication connection management table C. The entry is deleted, and the total number of fast path communication connections is updated (one is deleted). When there are a plurality of fast path communication connections set with the lowest priority, any one is deleted.

(S245)
The new fast path communication connection information is registered in the fast path communication connection management table C. At this time, the total number of Fastpath communication connections is updated (added one), and the priority information in the Fastpath communication connection management table C corresponds to the identification information in the priority identification information table B acquired in Step S243. Set priority information.

  After the above step S245, the fast path communication connection process is terminated, the process proceeds to step S12 (FIG. 9), and the normal packet process is continued.

As described above, the fast path communication connection priority control unit 2 acquires the information on the priority of the fast path communication connection corresponding to the packet to be transferred at high speed based on the information in the priority identification information table B, and determines the number of fast path communication connections. The fast path communication connection is preferentially controlled in accordance with the level of the priority so that the upper limit is not exceeded.
Therefore, in the second embodiment, even when the number of fast path communication connections reaches the maximum number of manageable fast path communication connections, a new fast path can be obtained during high-speed transfer of packets of the new fast path communication connection. When the priority of the existing fast path communication connection is identified by identifying the priority of the communication connection, and there is a connection that is lower than the priority of the new fast path communication connection among the existing fast path communication connections In addition, it is possible to give priority to a new fast path communication connection with a high priority by deleting the corresponding existing connection.

  Next, a specific example of the operation when the communication of the IP telephone terminal 400 is prioritized over the communication of the PC terminal 300 in the home gateway apparatus 100 accommodating the PC terminal 300 and the IP telephone terminal 400 will be described.

  Here, as shown in FIG. 10, a plurality of PC terminals 300 for the Internet are accommodated on the LAN side of the home gateway device 100, and a plurality of IP telephone terminals 400 for IP phones are accommodated. A description will be given assuming that P2P software or the like is used in a single PC terminal 300.

  Before the number of communication connections of the best effort type Internet communication in the PC terminal 300 reaches the upper limit value (for example, 4096) of the communication connections of the home gateway device 100 as a whole, the upper limit value (for example, 2000) of the number of fast path communication connections. The operation when a packet (session connection request) of a new communication connection from the IP telephone terminal 400 is received in a state in which it has been reached will be described. Assuming that an IP phone using the IP phone terminal 400 is a guarantee type service, it is assumed that priority should be given to a best effort type service using an Internet connection.

FIG. 11 is a diagram showing a specific example of the priority identification information table B in the second embodiment.
In FIG. The entry 1 is priority identification information in which a packet whose source address is the WAN-side IP address used by the home gateway apparatus 100 (HGW) for the IP telephone service is a priority “10”.
No. The entry of 2 is priority identification information in which a packet whose destination address is the IP address on the WAN side used by the home gateway apparatus 100 (HGW) for the IP telephone service is a priority “10”.
No. The entry 3 is priority identification information in which the IP address of the IP telephone terminal 400 subordinate to the LAN accommodated in the home gateway device 100 (HGW) is a packet whose source address is a priority “10”. .
No. The entry 4 is priority identification information in which the IP address of the IP telephone terminal 400 subordinate to the LAN accommodated in the home gateway device 100 (HGW) is a packet whose destination address is a priority “10”.
Note that the entry of the communication connection corresponding to the packet of the PC terminal 300 is not set. Therefore, “0” is registered in the fast path communication connection management table C as the communication connection priority of the PC terminal 300.

FIG. 12 is a sequence diagram illustrating a specific example of the priority control operation in the second embodiment.
The upper limit of the fast path communication connection that can be managed by the home gateway device 100 through communication between the network side NW 200 and the PC terminal 300 (PC (1) to (3)) via the home gateway device 100 (HGW). The operation of the priority control of the communication connection when the SIP INVITE packet of the session connection request is received from the IP telephone terminal 400 in a state of reaching (for example, 2000) is shown.

  First, the communication connection priority control unit 1 of the home gateway device 100 (IP: 192.168.1.1) receives a SIP INVITE packet (SRC: 192.168.1.2 DST: 192.168.1.1) from the IP telephone terminal 400 (IP: 192.168.1.2). Sometimes, it is confirmed whether the SIP INVITE packet matches the identification information in the priority identification information table B of FIG.

This SIP INVITE packet (SRC: 192.168.1.2 DST: 192.168.1.1) has a source IP address of No. 1 in FIG. Since it matches the entry 3, “10” is acquired as the priority of the new communication connection. Since the total number of communication connections has not reached the upper limit (for example, 4096) of manageable communication connections, nothing is deleted from the communication connection management table A, and the communication connection information of the SIP INVITE packet is registered in the communication connection management table A. To do. When registering, priority information of priority “10” is registered in the priority area. Since the SIP INVITE packet is a packet addressed to itself, it cannot be transferred by fast path. Therefore, the fast path communication connection priority control unit 2 does not register the new communication connection in the fast path communication connection management table C.
Thereafter, similarly, the communication connection of the SIP 200 OK packet from the network side NW 200 and the SIP ACK packet from the IP telephone terminal 400 is registered in the communication connection management table A. Further, since these packets cannot be transferred by the fast path, they are not registered in the fast path communication connection management table C.

Thereafter, when session connection is established between network side NW 200 and IP telephone terminal 400, communication using, for example, RTP (Real-time Transport Protocol) is performed.
When the RTP packet is transferred between the network side NW 200 and the IP telephone terminal 400, the communication connection with the priority “10” is similarly registered in the communication connection management table A.
Furthermore, since the RTP packet is a “transfer packet”, the fast path communication connection priority control unit 2 determines that the communication path can be transferred by fast path, and the upper limit of the number of fast path communication connections that can be managed by the total number of fast path communication connections. It is confirmed whether or not (for example, 2000) has been reached.
In this case, since the total number of fast path communication connections has already reached the upper limit (for example, 2000) that can be managed, the priority among the communication connections registered in the fast path communication connection management table C is “ Check if there is a Fastpath communication connection with a priority lower than "10".
In this case, since the priority of the communication connection using PC (1) to PC (3) is “0”, the fast path communication connection between the PC (1) to PC (3) and the network side NW 200 is One of the fast path communication connection entries is deleted from the fast path communication connection management table C, and the identification information of the fast path communication connection of the RTP packet is registered in the fast path communication connection management table C. When registering, “10” is set as priority information.

  In this way, by performing priority control of communication connections, SIP INVITE packets can transfer a high-priority RTP packet over the fast path by the dedicated OS 50 without imposing a load on the kernel 40. Become.

  As described above, according to the second embodiment, in the home gateway apparatus 100, the fast path communication connection priority control unit 2 is provided, and each fast path communication connection is managed while maintaining the priority. Even when the number of connections in communication reaches the maximum number of manageable Fastpath communication connections, check the priority of existing Fastpath communication connections and check for new Fastpath among existing Fastpath communication connections. When there is a fast path communication connection lower than the priority of the communication connection, it is possible to give priority to a new fast path communication connection with a higher priority by deleting the corresponding existing fast path communication connection.

  In the first and second embodiments, the example in which the priority at the terminal level is identified by the transmission source IP address and the destination IP address of the packet as the information for identifying the priority of the communication connection has been described. It is also possible to identify the priority level at the service level by using it as information for identifying the destination port number and the like. In addition, it is possible to identify the priority as identification information by combining a plurality of information from the IP header, TCP / UDP / ICMP header, and destination port of the packet. It is also possible to use information other than the example given in the priority identification information table B of FIG. 3 as identification information.

  In the first and second embodiments, the example of IPv4 is described as the IP protocol. However, the present invention can be similarly applied to an IPv6 communication connection.

  In the first and second embodiments, the example in which the present invention is applied to the home gateway apparatus 100 that accommodates a plurality of terminals and relays packets between the terminals and the communication network has been described. is not. In other words, the above-described operation is performed even in a communication device that transmits and receives packets to and from a plurality of terminals and discards received packets when the number of communication connections or the number of fast path communication connections with the terminals exceeds the upper limit. By applying, a similar effect can be achieved.

  In Embodiments 1 and 2, it is described that the number of communication connections and the number of fast path communication connections are set as the upper limit. However, the memory size used by the communication connection and the memory size used by the fast path communication connection (examples) : Byte designation) is also applicable.

  1 communication connection priority control unit, 2 fast path communication connection priority control unit, 10 WAN port, 20 LAN port, 30 application, 40 kernel, 50 dedicated OS, 100 home gateway device, 300 PC terminal, 200 network side NW, 400 IP Telephone terminal, A communication connection management table, B priority identification information table, C fast path communication connection management table.

Claims (8)

A gateway device that accommodates a plurality of terminals, relays packets between the terminals and the communication network, and discards received packets when the number of communication connections between the terminals and the communication network exceeds an upper limit. And
A part of information included in the packet as identification information, a priority identification information table storing priority information of communication connections,
A communication connection management table in which the identification information and the priority information corresponding to the identification information are stored for each communication connection established between the terminal and the communication network and the gateway device;
Based on the information in the priority identification information table, information on the priority of the communication connection corresponding to the packet to be transmitted / received is acquired, and the communication connection is determined according to the level of the priority so that the number of communication connections does not exceed the upper limit. And a communication connection priority control unit for performing priority control of the gateway device. The communication connection priority control unit
When the number of communication connections has reached the upper limit, when transmitting / receiving a packet of a new communication connection that is not registered in the communication connection management table,
Based on the information in the priority identification information table, obtain information on the priority of the new communication connection,
2. The gateway apparatus according to claim 1, wherein communication connections lower than the priority of the new communication connection are deleted from the communication connection priorities registered in the communication connection management table. Of the communication connections established between the terminal and the communication network and the gateway device, for each communication connection to be subjected to high-speed transfer, the identification information and the priority information corresponding to the identification information, Is stored in the Fastpath communication connection management table,
Based on the information in the priority identification information table, obtain information on the priority of the communication connection corresponding to the packet to be transferred at high speed, so that the number of communication connections subject to high-speed transfer does not exceed the upper limit of the fast path communication, A fast path communication connection priority control unit that preferentially controls a communication connection to be subjected to high-speed transfer according to the level of the priority;
The gateway device according to claim 1, further comprising: The fast path communication connection priority control unit
When the number of communication connections subject to high-speed transfer has reached the maximum number of fast path communication, when transferring a packet of a new communication connection that is not registered in the fast path communication connection management table at high speed,
Based on the information in the priority identification information table, obtain information on the priority of the new communication connection to be subjected to high-speed transfer,
4. The communication connection lower than the priority of the new communication connection is deleted from the priorities of communication connections to be subjected to high-speed transfer registered in the fast path communication connection management table. Gateway device. At least one of the plurality of terminals is an IP telephone terminal;
2. The priority of a communication connection corresponding to a packet transmitted / received by the IP telephone terminal is set higher than a priority of a communication connection corresponding to a packet transmitted / received by a terminal other than the IP telephone terminal. The gateway apparatus as described in any one of -3. The gateway device according to claim 1, wherein the identification information is at least one information of an IP header, a TCP / UDP / ICMP header, and a destination port of the packet. A communication device that transmits and receives packets to and from a plurality of terminals and discards received packets when the number of communication connections with the terminals exceeds an upper limit,
A part of information included in the packet as identification information, a priority identification information table storing priority information of communication connections,
A communication connection management table in which the identification information and the priority information corresponding to the identification information are stored for each communication connection established between the terminal and the communication device;
Based on the information in the priority identification information table, information on the priority of the communication connection corresponding to the packet to be transmitted / received is acquired, and the communication connection is determined according to the level of the priority so that the number of communication connections does not exceed the upper limit. And a communication connection priority control unit that preferentially controls the communication device. A communication connection management method for a communication apparatus that transmits and receives packets to and from a plurality of terminals and discards received packets when the number of communication connections with the terminals exceeds an upper limit.
A part of information included in the packet as identification information, the step of setting communication connection priority information;
Creating the identification information and priority information corresponding to the identification information for each communication connection established between the terminal and the communication device;
Obtaining priority information of a communication connection corresponding to a packet to be transmitted and received;
And a step of preferentially controlling the communication connections in accordance with the level of the priority so that the number of communication connections does not exceed the upper limit.

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